Draft: Pack to rawbank algorithms

A new algorithm to pack particles and other objects to directly to raw bank. Currently only part of PackParticlesAndVertices is migrated. Rest to be done when needed.

Current status:

• templated PackParticlesAndVerticesToRawBank algorithm packs particles, vertices, flavortags, muon and rich PIDS (maybe others can be added as well)
• Compressor algorithm takes in PackedDataBuffers from packers above and put them in a raw event
• a new decoder algorithm produces PackedDataBuffers (similar to HltPackedDataDecoder)
• unpackers that take in PackedDataBuffers as input
• a simple packer/unpacker for v2 particles to be used as template for other v2 objects
• add support for child indexing
• proper location mapping, currently done manually in test script
• more realistic testing (within Moore framework with real inputs)
• better naming, namespacing, directory structures, debug messages
• add the missing checks (checksum, packing, unpacking...)

For testing use with Phys!936 (closed) Phys/ParticleConverters/tests/convert_particles.py which creates dummy particles and vertices, and then follows the steps above.

Follows the discussion on !2904 (merged) @jonrob @erodrigu